W wit-nesses



No.625,l85. Patnted May l6, I899.

T. B. L. MITCHELL.

SEWER TRAP.

(No Model.)

- WITNEEEE5 INVEN'T cm- I WW I M UNITED STATES PATENT OFFICE.

TIMOTHY B. L. MITCHELL CF BALTIMORE, MARYLAND, ASSIGNCR, BY DIRECT ANDMESNE ASSIGNMENTS, TO J. VERNON CAMPBELL, OF SAME PLACE.

SEWER-TRAP.

SPECIFICATION forming part of Letters Patent No. 625,185, dated May 16,1899.

Application filed November 26, 1898. Serial No. 697,521. (No modeli) T0ctZZ whom it may concern..-

Be itknown that I,TIMOTHY B. L. MITCHELL, of the city of Baltimore, inthe State of Maryland, have invented certain Improvements inSewer-Traps, of which the following is a specification.

In the description of the said invention which follows reference is madeto the accompanying drawings, forming a part hereof, and in which-Figure 1 is a central longitudinal section of the improved sewer-trap.Fig. 2 is a transverse section of Fig. 1, taken on the dotted line 00as. Fig. 3 is a plan or top view of the invention.

Referring now to the drawings, A is the shell of the trap, open at thetop and having at one end the bell a and at the other the plain beadednozzle l), whereby it is adapted for insertion in a line of sewerconnectionpipes. The top of the shell is flat and the bottom rounded inboth directions, and it projects below the ends, thus forminga basin orreceptacle 0 for water. The water-line is represented by a dotted linemarked .2 in Fig. 1. The sides of the shell are flat and vertical, for apurpose hereinafter described.

B is a curved plate secured within the shell by means of bolts d, whichpass through lugs 0 f and the sides of the shell.

By making the sides of the shell flat and vertical, as shown in Fig. 2,the curved plate Bis easily inserted through the opening in the top, andno difficulty is experienced in making the edge of the plate fit closelyto the sides of the shell.

The lower edge of the curved plate B extends a short distance below thewater-line .2, so as to form a water seal and prevent the passage ofgases from the sewer.

The transverse area of the basin or space below the lower edge of thecurved plate B is about the same as that of the nozzle b. Consequentlythe velocity of the water passing through the basin corresponds withthat discharged from the trap.

The shell is covered by a top or lid D, in which is a manhole E, andupon the flange g, within the manhole, is erected a pipe F, leading tothe surface of the ground, where it is provided with a removable plateC.

By having the hollow or concave surface of the plate B presented to theincoming water any sticks or other bodies entering the shell are drivenunder the edge of the plate, and the velocity of the water in ordinarycircunn stances will keep the. bottom of the basin clean or free from anaccumulation of mud and sand; but should sand or mud collect from anycause Whatever in the basin it may be dislodgedby forcing a current ofwater from a water-main through the space below the curved plate. Toprovide for this cleans= ing operation, I form on the shell, at a pointin front of the curved plate, a small nozzle h and into it insert a pipej, which extends to a water-main or service-pipe and provide thesaidpipe with a cook it, which may be operated from the surface of theground. This pipe, with its cock, is shown in Fig. 1.

I claim as my invention- In a sewer-trap, the shell thereof havingarounded bottom and straight vertical sides, combined with a curved plateremovably se= cured to the sides thereof, the lower edge of the saidplate extending downward below the water-line in the shell, a removablelid, and a flushing-pipe situated below the lower edge of the saidcurved plate,substantially as specified.

TIMOTHY B. L. MITCHELL. WVitnesses:

WM. T. HOWARD, HARRY CONSTANTINE.

